Free Rare Card After 5 "New Signing" Pickups

I just purchased my 5th rare player expecting to get a free rare card until I realized these purchases need to come from the New Signing marketplace. I believe you also have to have started playing SoRare with someone's referral code. Problem I have is I cant remember if I used someone's referral code when I started and I only need 2 more New Signing pickups. Is there a way to see if I used someone's referral code? Would rather not pickup more New Signings players if I don't have to and just pick up from the regular marketplace.